Mechanical hammer.



J. S. KNOWLSON.

MECHANICAL HAMMER.

APPLICATION FILED rnBils, 1913.

" 1,082,880. I Patented Dec.30,1913.

X I I I l I I I p to the type of'hammers invol 'ing,

ahrelatively. high speed without drag,

[ nnirnnstrarus Parana orrion;

JAMES S. KNOWLSON, OF LA GRANGE ILLINOIS, ASSIGNOR 'IO ELECTED-MAGNETIC I -TOOL COMPANY, or CHICAGO, ILLINOIS,

A CORPORATION OF ILLINOIS.

MECHANICAL HAMMER.

Specification of Letters Patent. Application filed February 15, 1913. Serial No. 748,547.

PatentedDec.30,1913.

To all whom it may concern Be it known that I, Janus S. Kxowilson, a citizen of the United States, residing at La'Grange, in the county of Cook and State of Illinois, have invented a new and useful lrorovement in Mechanical Hammers, of -h theiollowing is a: specification. My invention relates, more partieuhu to mechanical hammers for deliv against a reciprocahle tool, as for a rock, stone or cement drill, and

stated, a rotarymember equipped lll piv 'oted hammers which swing outwardly under centrifugal force to a position where they will deliver blows to the. tool, and rebound, after striking the tool, to aposition in which they will clear the tool. 7

My objects, generally stated, are to provide a hammer-f the type ahove referred to-which will operate to deliver sharp clean:

blows against the toohand may be operated or rebound, against the tool.

A further object is to reduce wearof the pving parts to the minimum; and to so arrange the hammers'that the blows produced thereby, when rebounding against t e rotar member to which they are piv- Oted, wil tend to accelerate said rotary member rather than decelerate it.

Referring to the accompanying drawing Figure 1 1s a view lntelevation of a hand-- hammer constructed in accordance with my invention. Fig. 2 Isa section taken at the line 2 on Fig. 1 and viewed in the direction 0 the arrow, this view showing by full lines the pivoted hammers in the positions they assume-when the mechanism is at rest, the dotted circle indicating the path through which the outer edges of the pivotedhammers travel when swung outwardly on their r'otary support by the action of centrifugal force Fig. 3 is a view taken atthe line 3 2 011 Fig. 2 and viewed in the direction of the,

arrow; and Fig/4, a perspective viewdo f one 0f the-two similar hammersemployed.

The casing for the hammermechanism is illustrated at 5 and is formed at its upper end witha hand-grip (3, and at its lower end with a sleeve-section 7 containing a hearing member, 8, the aperture 9 th-erethrough, pref-- I crably being of angular shape in cross-sec of the latter.

tion, this hearing serving to receive and guidcdiy confine a too] such as that represented at 10, the latter being provided with a section ll, corresponding in cross section. with the shape of the opening 9 and slid-able therein, and a shouldered section 12 woich the casing 5 is adapted to bear in the operation of the mechanism, the shoulder 12 being so disposed that it will cause the upper end of the tool to extend into a position, in the interior of the casing 5, wherein it will receive the blows delivered by the hammers hereinafter described.

Journaled in bearings 13 on the casing 5 is a shaft- Li, provided with an operatinghandle 15 and carrying a gear 16 which mesheswith a pinion 17 fixed on a shaft 18 journaled in hearings 19in the casing. The shaft 18 has rigidly secured thereto a bar 20 which extends at right angles to said shaft and preferably cquidistantly beyond theopposite sides thereof. The bar 20, which is adapted to be rapidly rotated by turning the crank 15, forms the support for hammers 21, which are pivoted as indicated at to this har ioward thc opposite ends in the construction illustrated the hauuucrs 21 are recessed as indicated at 23, thereby affording spaced sections .Zalat which the. hammers strad 'lle bosses provided on the bar :20 and extending inoppositedirections thereon, the pivot-pins 22 pa -mg bos .s 2:. The bosses 25 are preferably so disposed as to cause the pins 22 to he diametrically opposed about the shaft 18 as reprcscnted in Fig. 2, and disposed at opposite sides oi said bosses are stopsurfaces 2e and 2?, withwhich the surfaces :38 aiitl 29 against through the sections and the or the hammers 3] are adapted ltlsp ci ltfcly to coiipcrate for striking position and serving as stops there for uponrelround of the hammers, respectivcly the opposite ends of the bar 20 adjac nt to its stop-surfaces 2i; being bifurcated as represented z t-30.

The. various pal he mocha ism described are so air as illustrated, as to cause the huu'uner when swung outs wardly lo the full line position represented of the lowermost hammer in Fig. 2 and the holding the hammers in dotted position represented of the hammer in theuppcr part of this figure, to be in position for striking against the upper end of the tool 11 While traversing the path represented by the dotted circle :0, the ends of the bar 20, as the latter is rotated, passing at their bifurcated portions 30 over the upper end of the drill 10. The) hammers 21, upon striking the drill 10, are swung backward, by force of the impact, and toward the axis of rotation of the bar- 20, into engagement at their surfaces 29 with the stop-surfaces 27 and into engagement with bosses 31 pro vided on the bars 20.

It is highly desirablein a mechanism of this character that clean sharp blows be delivered by the hammers againstthe tool and that rebound of the hammers against the driltbe prevented. To these ends I so dispose the stop-surfaces 26 and the pins 22 as to cause the centers of gravity ofthe ha1 nmers to be in the rear of the pivots 22, whereby centrifugal force will cause the hannners 21., in returning to striking position, after delivering a blow against the drill, to be held against the stop-surfaces 26 which are so disposed as illustrated as to cause the blow delivered by the hammers to be tangential to a circle described about the axis of the shaft 22; and so dispose the stop-surfaces 27 on the bar 20 as to cause the hammers 22 to swing through a relatively greatarc lll opposition .to centrifugal force, after striking the drill, whereby centrifugal force is utilized to cushion in a measure the force of the hammer in swinging backu'ardl as stated, which serves to reduce the blow of the hammer against the cooperating stop surface 27, thus minimizing arring of the moving parts of the mechanism. \Vith a view to further reducing the jarring of the parts of the mechanism and the subjection tool 'and against the bar 20 are caused to travel through an arc of relatively largedes" grce before striking the stop-surfaces with the advantage lna'einbclore pointed out.

While I have illustrated and described a particular construction. of hammer-mechanism embodying my invention, I: do not wish to be understood as intending to limit it to such cmistruction as the same may be varithe pivots 22, the hammers upon rebounding from the hammer pivoted thereto and adapted to be moved Into st rlklng pOSEllOll by centrlfugal force. the pivot of said hammer being so-located rclati\-' e'to the axis about which 'said rotary member turns, as to cause said ha'mmer on recoiling to strike against said rotary member wholly intermediatethe axis of rotation of the latter and the pivot of said hammer.

2. In a device of the character set forth, the combination of a rotary member, and hammers pivoted thereto inbalanced condition about the axis of said rotary member and adapted to be moved into striking position by centrifugal force, the pivots of said hammers bring so locatcd relative to the axis about which said rotary member turns, as to cause said rotary hammers'on recoiling to strike against said rotary member wholly intcrmediate the axis of rotation of the latter and'the respective pivots of. said hammers. Y

3. In a device of the character set forth, the combination of arotary mcmber, and a hammer pivoted thereon aml adapted to be moved into striking position-by centrifugal force. said rotary member being. provided with a stop-surface -for saidhammcr during recoil located wholly between the axis upon which said hammer turn'sand the axis of said rotary member and in :ulvanceot'the axis of said hammcr, whereby said hammcr in recoiling "strikes said rotary: member wholly between the axis upon, which the hammer turns and the axis of the rotary member, for thc purpcsc set forth. o q

-l. in a device of the character N.t f(ll'tll, the combination of a (me-piece rotary membcr, providedwith bosses at its opposite ends and flanked by inner and outcg; stopsurfaces. and hammers pl cotcd on said bosses" and adaptcd to be moved into; striking position by ccntril'ugal force and bear against said outer stop-surt'a 'cs, thepivots of said hammcrs being St),lt)(f:ltt!l1,l}lilllVtE to the axis (it"s-lid rotary mcmbcr'; to cause said hammers on rccoiling, to .stiilge said inner stop-surfaccs on said rotary;member, 

